I've been using buprenorphine as an antidepressant for 13 months now, and the more conventional poppy-derivatives for at least a year before that.
I haven't been willing to let my doctors dismiss my complaints of
pain, anhedonia and bedtime insomnia (and weird 36-48 hour sleep cycles) by prescribing the SSRI of the month, or Effexor, although I've had doctors insist upon both to try to hurry me out of their office (and by prescribing another drug, they get to bill the 5 minute visit as a "high-complexity office visit - $200").
My quality of life definately improved dramatically during this period, initially (2.5 years ago) my sleep improved, and my recreational alcohol, weed and meth intake stopped, both of which I attribute to my self-medicational use of opioids.
Not everybody can safely self-medicate with opioids, in fact I would strongly advise against it, because it is FAR too easy to fall into the trap of falling in love with "the nod", or placing the drugs on a pedestal as infallable cures for all that ails you. I believe there were 3 factors which helped me control my usage above all others...
#1 I found a passion in learning all that I could about opioids, and knowing everything there is to know about its pharmacology and chemistry (and history and sociological factors) BEFORE ever using them.
#2 I STRONG belief that moderation is EXTREMELY important in using ANY drug, and a love for the principles of harm-reduction. I've always limited my consumption essentially only to what I NEED (or more specifically, the dose which would provide me the most benefits with the least harms), and didn't do recklessly large amounts, and always strived to ration out my supply to last as long as possible (which helped me both financially and with my tolerance)
#3 I have always taken great care to opioids in easily measurable forms, primarily pharmaceutical quality pills, and I've always used a milligram scale and a measuring syringe whenever appropriate to assure that the dosage I injested was always predictable and reasonable.
Believe me, if you take great care to NOT do 40mg lines of Oxy every time you feel like it, you'll be MUCH better off one day in the future when you break some toes and decide to eat an OC10, and you experience 12 hours of blissful RELIEF.
To anybody who NEEDS an opioid in their life, either long term or short term, for one reason or another (pain, depression, dependance, addiction), I strongly recommend considering
Buprenorphine, as it has made my life easier and more bearable for more than a year now, and my tolerance has not increased at all... I still experience pain-relief from it, though it never produced unwanted sedation, nausea, apathy, or cognitive issues. I've been using right around 2mg for the last 13 months, in 2-4 divided doses per day either orally or nasally (depending on whether I'll need to talk to anybody for 15 minutes or so).
To those who suffer the primary side effect of the opioids, remember FIBER and MAGNESIUM are enough to return you to your pre-opioid function. IF those aren't enough, look into "Polyethylene Glycol 3350 powder", its a lifesaver!
If somebody in this thread is looking for some references for further reading, look no further than:
http://hive.dopers.org/bupe_for_depression.txt
http://hive.dopers.org/buprenorphine.txt
http://opioids.com/buprenorphine/buprefdep.html
http://www.dr-bob.org/babble/20041211/msgs/428827.html
I know this isn't a research paper or anything (I do plan to write one on this subject someday - tonight is NOT the night, I've got a trip to pack for), but I feel my personal experience answers the original question just as well as any study could (while I acknowledge that my sample size here is 2 - the other party wishes to remain nameless).